To date, the clinical assessment of joint pathology, such as ligament injuries, equinus and other joint deformities, is subjective in nature. The clinician primarily relies on the manual manipulation of the joint. During clinical examination, the clinician obtains a subjective "feel" for the amount of laxity or stiffness that is present in the involved joint as compared to the clinician's previous experience regarding what the normal joint stiffness should feel like and/or as compared with the intact contralateral joint. This clinical examination is then supplemented by the patient clinical history and by radiological evaluations. Moreover, the assessment of the effectiveness of treatment, be it cast therapy, surgery, etc., is completely subjective and relies to a great extent on feedback from the patient. Consequently, there is a need for a quantitative, reliable technique to assess the flexibility of a joint for the purposes of contributing to the clinical management of joint pathologies.
Aside from the need for a more objective assessment of joint pathologies, there is also a need for providing an objective analysis in the design and evaluation of footwear. That is, there is a need to determine the level of support (three dimensional load-displacement and flexibility characteristics) provided to a joint such as the ankle joint by athletic footwear and to evaluate the quality of fit of this footwear. Currently, athletic shoes and other foot and ankle supporting devices are designed purely on an intuitive basis. There is no objective means for determining the quantitative support provided by a particular footwear design to provide the designer with sufficient feedback to rationally modify the design of the footwear for better performance.
The present invention is directed to an apparatus and method which will allow a clinician and footwear designer to determine the load-displacement and flexibility characteristics of a joint and footwear, respectively. The present invention is directed to ascertaining the angular and linear displacement of the joint about and along its pivot axes produced in response to applied torques and forces about and along the axes. Accordingly, the present invention provides an objective quantitative, reliable technique to assess the load-displacement and flexibility characteristics of anatomical joints which greatly contributes to the clinical management of joint pathologies as well as to the design of footwear.